【作者】 冯秋霞；

【导师】 蒋国平；

【作者基本信息】 大连理工大学 ， 物理电子学， 2007， 硕士

【摘要】 随着开关电源技术的迅速发展，DC／DC开关电源IC已在通信、计算机以及消费类电子产品等领域得到了广泛应用。近年来，电池供电便携式设备的需求越来越大，对DC／DC开关电源IC的需求也日益增大，同时对其性能要求也是越来越高。为适应便携式电子产品的应用要求，本文基于0.6μm BiCMOS工艺，利用EDA Pspice集成电路设计工具设计了一款同步降压型DC／DC开关电源管理的IC。本文设计的这款IC具有使能控制功能，基本工作方式为PWM调制方式，在实现较高开关频率的同时，也保证了电路在重载或轻载下都有着较高的转换效率；为了消除浪涌电流的影响和降低对输入电容的要求，电路也具有软启动控制功能；同时通过限流保护电路，避免了过流情况的发生；另外，该集成电路也有过热保护功能和欠压锁定功能，当电路发生过热或者欠压等意外故障情况时，整个电路自动关断，直到故障消除为止。通过Hspice仿真工具对各个模块电路以及整体电路都进行了仿真验证，结果表明该集成电路工作稳定，各项指标都达到了设计要求。具有高达2.4MHz的PWM开关频率，2.7V-5.5V电源电压输入范围，输出电压在0.6V-2.5V之间可调，转换效率最高达到81.5％。由上可见，该DC／DC电源管理IC采用同步整流技术提高了效率，并省去了常规降压型DC／DC转换器中所需的外部肖特基二极管。可以优先用于考虑小尺寸和高效率的应用，允许用户牺牲部分效率来换取更小的外部元件。本文最后对整体电路的版图进行了布局，并利用Cadence下版图设计工具Virtuoso和验证工具Dracula对部分模块电路进行了版图设计和验证。通过对版图的布局以及对电路功能等方面进行考虑，该集成电路可满足小封装要求，可应用在手机、PDA以及MP3播放器等便携式电子产品中。更多还原

【Abstract】 With the rapid development of the switching power supply technology, the DC/DC switching power supply IC has already obtained the widespread application in domains such as communication, computer, and consumptive electronics. In recent years, the demand of portable equipment with battery power supply expands more and more quickly, so does the the DC/DC switching power supply IC. What is more, it requires its performance to become better and better. In order to adapt to the application requirement of portable electronic products, based on the 0.6μm BiCMOS process, the paper designs a synchronous step-down DC/DC switching power supply management IC by using the EDA tools Pspice.The IC this paper designs has enabling control function, working with PWM modulation. While achieving a higher switching frequency, it can also ensure higher conversion efficiency either the circuit has heavy or light load. In order to eliminate the impact of the inrush current and lower the input capacitance value, the circuit has soft-start control function. Over current situation is avoided by current-limiting protection circuits, also, this IC has over temperature protection and undervoltage lockout function. That means when the circuit suddenly has faults such as over temperature or undervoltage, the whole circuit will shutdown automatically until the faults are eliminated. By using the tools of Hspice, every sub-circuit and the whole circuit are simulated, and the results show that this IC works stably and every indicator achieves the design requirement. The PWM switching frequency reaches 2.439MHz. The input voltage range is 2.7V-5.5V, and the output voltage can be changed from 0.6V to 2.5V. The conversion efficiency reaches 81.5%.From above on, this DC/DC switching power supply management IC uses synchronous rectification technology, which improves efficiency and omits the external schottky diodes used in conventional step-down switching power supply management IC. It can be used in applications priority to consider both of small size and high efficiency, because it allows users to sacrifice part of efficiency in exchange for smaller external components.At the end, this paper positions the whole circuit layout. Then it designs the layout for some module circuit and checks it by using Cadence Virtuoso and Cadence Dracula. Considering the layout and the function of the whole circuit, this IC meets the requirement of small package, and it can be applicated in mobile phones, PDAs, MP3 players and other portable electronic products.更多还原